Adding information for NETINFO environmental variable (#463)

* Adding information for NETINFO environmental variable
* Changing variable to ELASTIC_NETINFO
* Set default ELASTIC_NETINFO:false

Author: gizas

docs/en/ingest-management/elastic-agent/configuration/env/container-envs.asciidoc

@@ -48,6 +48,9 @@ include::shared-env.asciidoc[tag=kibana-password]
 
 include::shared-env.asciidoc[tag=kibana-ca]
 
+include::shared-env.asciidoc[tag=elastic-netinfo]
+
+
 |===
 
 [discrete]

docs/en/ingest-management/elastic-agent/configuration/env/shared-env.asciidoc

@@ -560,4 +560,20 @@ contains your CA's certificate.
 
 // end::kibana-ca[]
 
+// tag::elastic-netinfo[]
+|
+[id="env-{type}-elastic-netinfo"]
+`ELASTIC_NETINFO`
+
+| (bool) When `false`, disables `netinfo.enabled` parameter of `add_host_metadata` processor.
+Setting this to `false` is recommended for large scale setups where the host.ip and host.mac fields index size increases.
+
+By default, {agent} initializes the `add_host_metadata` processor. The `netinfo.enabled` parameter defines ingestion of IP addresses and MAC addresses as fields `host.ip` and `host.mac`. 
+For more information see <<add_host_metadata-processor>>
+
+
+*Default:* `"false"`
+
+// end::elastic-netinfo[]
+
 // =============================================================================

docs/en/ingest-management/elastic-agent/scaling-on-kubernetes.asciidoc

@@ -135,7 +135,7 @@ Setting the low priority to {agent} comparing to other pods might also result to
 Trying to prioritise the agent installation before rest of application microservices, https://github.com/elastic/elastic-agent/blob/main/docs/manifests/elastic-agent-managed-gke-autopilot.yaml#L8-L16[PriorityClasses suggested]
 
 [discrete]
-=== {k8s} Policy Configuration
+=== {k8s} Package Configuration
 
 Policy configuration of {k8s} package can heavily affect the amount of metrics collected and finally ingested. Factors that should be considered in order to make your collection and ingestion lighter:
 
@@ -145,9 +145,21 @@ Policy configuration of {k8s} package can heavily affect the amount of metrics c
 - Disable events dataset
 - Disable {k8s} control plane datasets in Cloud managed {k8s} instances (see more info ** <<running-on-gke-managed-by-fleet>>, <<running-on-eks-managed-by-fleet>>, <<running-on-aks-managed-by-fleet>> pages)
 
+
+[discrete]
+=== Dashboards and Visualisations 
+
+The https://github.com/elastic/integrations/blob/main/docs/dashboard_guidelines.md[Dashboard Guidelines] document provides guidance on how to implement your dashboards and is constantly updated to track the needs of Observability at scale.
+
 User experience regarding Dashboard responses, is also affected from the size of data being requested. As dashboards can contain multiple visualisations, the general consideration is to split visualisations and group them according to the frequency of access. The less number of visualisations tends to improve user experience.
 
-Additionally, https://github.com/elastic/integrations/blob/main/docs/dashboard_guidelines.md[Dashboard Guidelines] is constantly updated also to track needs of observability at scale.
+[discrete]
+=== Disabling indexing host.ip and host.mac fields 
+
+A new environemntal variable `ELASTIC_NETINFO: false` has been introduced to globally disable the indexing of `host.ip` and `host.mac` fields in your {k8s} integration. For more information see <<agent-environment-variables>>.
+
+Setting this to `false` is recommended for large scale setups where the `host.ip` and `host.mac` fields' index size increases. The number of IPs and MAC addresses reported increases significantly as a Kubenetes cluster grows. This leads to considerably increased indexing time, as well as the need for extra storage and additional overhead for visualization rendering.
+
 
 [discrete]
 === Elastic Stack Configuration